Diabetes Cardiovascular Disease Review


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Diabetes Cardiovascular Disease Review

  1. 1. Diabetes &Cardiovascular A Publication of the American Diabetes Association / American College of Cardiology Make the Link! Initiative Disease Review Issue 6: Peripheral Arterial Disease in Diabetes Peripheral Arterial Disease in Diabetes P eripheral arterial disease (PAD) is a condition characterized by athero- sclerotic occlusive disease of the lower extremities. PAD is a major risk factor for lower-extremity amputation and revealed that 20% of symptomatic patients with PAD had diabetes, but this statistic probably greatly underestimates the preva- lence, given that many more people with PAD are asymptomatic. It has been tibial (below the knee) PAD, whereas other risk factors (e.g., smoking and hypertension) are associated with more proximal disease in the aorto-ilio-femoral vessels. is also accompanied by a high likelihood reported that of the people with PAD, over The true prevalence of PAD in people for symptomatic cardiovascular and cere- one-half are asymptomatic or have atypi- with diabetes has been difficult to deter- brovascular disease. Although much is cal symptoms, about one-third have mine, because most patients are known about PAD in the general popula- claudication, and the remainder have asymptomatic, many do not report their tion, the assessment and management of more severe forms of the disease.2 symptoms, there is not uniform agreement PAD in individuals with diabetes is less The most common symptom of PAD is on screening modalities, and pain percep- clear. At present, there are no established intermittent claudication, defined as pain, tion may be blunted by the presence of guidelines regarding the care of patients cramping, or aching in the calves, thighs, peripheral neuropathy. For these reasons, with both diabetes and PAD. or buttocks that appears reproducibly a patient with diabetes and PAD may be The American Diabetes Association with walking exercise and is relieved by more likely to present with an ischemic recently conducted a consensus confer- rest. More extreme presentations of PAD ulcer or gangrene than a patient without ence to review current knowledge include rest pain, tissue loss, or gangrene; diabetes. regarding PAD in diabetes. After lectures these limb-threatening manifestations of The reported prevalence of PAD is also by experts in the fields of endocrinology, PAD are collectively termed “critical limb affected by the methods by which the cardiology, vascular surgery, orthopedic ischemia” (CLI). diagnosis is sought. Two commonly used surgery, podiatry, and nursing, a vascular PAD is also a major risk factor for tests are the absence of peripheral pulses medicine panel developed a consensus lower-extremity amputation, especially in and the presence of claudication. Both, statement that addressed the epidemiol- patients with diabetes. Moreover, even for however, suffer from insensitivity. A more ogy, impact, biology, and evaluation and the asymptomatic patient, PAD is a accurate test is the ankle-brachial index treatment of PAD in diabetes. marker for systemic vascular disease (ABI), which involves measuring the This article includes excerpts from the involving coronary, cerebral, and renal systolic blood pressures in the ankles statement published in Diabetes Care vessels, leading to an elevated risk of (dorsalis pedis and posterior tibial arteries) (December 2003). To access the full state- events, such as myocardial infarction (MI), and arms (brachial artery) using a hand- ment, visit http://care.diabetesjournals.org/ stroke, and death. held Doppler and then calculating a ratio. cgi/content/full/26/12/3333. Diabetes and smoking are the strongest Simple to perform, it is a noninvasive, risk factors for PAD. Other well-known quantitative measurement of the patency of Epidemiology and Impact of PAD risk factors are advanced age, hyperten- the lower-extremity arterial system. The in Diabetes sion, and hyperlipidemia.3 ABI has been validated against angiograph- PAD affects 12 million Americans. Data In people with diabetes, the risk of ically confirmed disease and found to be from the Framingham Heart Study1 PAD is increased by age, duration of 95% sensitive and almost 100% specific.4 diabetes, and presence of peripheral There are some limitations, however, in neuropathy. African Americans and using the ABI. Calcified, poorly compressi- Hispanics with diabetes have a higher ble vessels in the elderly and some patients What’s Inside prevalence of PAD than non-Hispanic with diabetes may artificially elevate values. ‹ Reproducible patient page: whites, even after adjustment for other The ABI may also be falsely negative in All About Peripheral Arterial Disease known risk factors and the excess preva- symptomatic patients with moderate lence of diabetes. Diabetes is most strongly aortoiliac stenoses. These issues complicate associated with femoral-popliteal and the evaluation of an individual patient but
  2. 2. 2 Diabetes & Cardiovascular Disease Review Issue 6 are not prevalent enough to detract from patient who has a high risk of subsequent Table 2. the usefulness of the ABI as an effective test MI or stroke regardless of whether PAD to screen for and diagnose PAD in patients symptoms are present and 2) to treat Criteria for Testing for PAD with diabetes. symptoms of PAD, which may be associ- Using the ABI Using the ABI, one survey5 found a ated with functional disability and limb 1. Perform a screening ABI in patients prevalence of PAD to be 20% in people loss. PAD is often more subtle in its pres- with diabetes who are >50 years of with diabetes >40 years of age. Moreover, entation in patients with diabetes than in age, and, if normal, repeat the test another survey of patients with diabetes individuals without diabetes. In contrast every 5 years. >50 years of age showed a prevalence of to the focal and proximal atherosclerotic 2. Consider a screening ABI in patients PAD of 29%.6 lesions of PAD found typically in other with diabetes who are <50 years of high-risk patients, in diabetic patients, the age and have other PAD risk factors Impact of PAD. The impact of PAD can lesions are more likely to be more diffuse (e.g., smoking, hypertension, hyper- be assessed by its progression, its symp- and distal. Importantly, PAD in diabetes is lipidemia, or duration of diabetes toms, and the excess cardiovascular events usually accompanied by peripheral >10 years). associated with systemic atherosclerosis. neuropathy with impaired sensory feed- 3. Perform a diagnostic ABI in any Approximately 27% of patients with PAD back. Thus, a classic history of patient with symptoms of PAD. demonstrate progression of symptoms claudication may be less common. over a 5-year period, with limb loss occur- However, a patient may elicit more subtle ring in 4%. While the majority of patients symptoms, such as leg fatigue and slow are many alternative causes of leg pain on remain stable in their lower-limb sympto- walking velocity, and simply attribute exercise, including spinal stenosis, and matology, there is a striking excess them to getting older. It has been reported they should be excluded. PAD patients cardiovascular event rate over the same 5- that patients with PAD and diabetes expe- present along a spectrum of severity, rang- year time period, with 20% sustaining rience worse lower-extremity function ing from no symptoms, intermittent nonfatal events (MI and stroke) and a than patients with PAD alone.9 Also, claudication, and rest pain to nonhealing 30% mortality rate.7 For individuals with diabetes patients who have been identified wounds and gangrene. CLI, the outcomes are worse: 30% will with PAD are more prone to the sudden A thorough walking history will elicit have amputations and 20% will die within ischemia of arterial thrombosis or may claudication symptoms. Because these 6 months.8 The natural history of PAD in have a pivotal event leading to neuro- symptoms are often not reported, patients patients with diabetes has not specifically sichemic ulceration or infection that should be asked specifically about them. been studied longitudinally, but it is rapidly results in an acute presentation Two important components of the physi- known from prospective clinical trials of with critical limb ischemia and risk of cal examination are visual inspection of risk interventions that the cardiovascular amputation. By identifying a patient with the foot and palpation of peripheral event rates in patients with PAD and subclinical disease and instituting preven- pulses. Dependent rubor, pallor on eleva- diabetes are even higher than those of tative measures, it may be possible to tion, absence of hair growth, dystrophic their nondiabetic counterparts. avoid acute, limb-threatening ischemia. toenails, and cool, dry, fissured skin are Diagnosing PAD is of clinical impor- PAD in diabetes also adversely affects signs of vascular insufficiency and should tance for two reasons: 1) to identify a quality of life, contributing to long-term be noted. The interdigital spaces should disability and functional impairment that be inspected for fissures, ulcerations, and is often severe. Patients with claudication infections.10 Table 1. have a slower walking speed (generally <2 Palpation of peripheral pulses should mph) and a limited walking distance. This be a routine component of the physical Diagnostic Criteria for PAD may result in a “cycle of disability” with examination and should include assess- Using the ABI progressive deconditioning and loss of ment of the femoral, popliteal, and pedal ABI function. Finally, there are significant vessels. It should be noted that pulse economic costs of health care, reduced assessment is a learned skill and has a 0.91–1.30 Normal productivity, and personal expenses asso- high degree of interobserver variability, 0.70–0.90 Mild obstruction ciated with a chronic manifestation of with high false-positive and false-negative 0.40–0.69 Moderate obstruction atherosclerotic disease such as PAD. rates. The dorsalis pedis pulse is reported to be absent in 8.1% of healthy individu- <0.40 Severe obstruction Diagnosis and Evaluation of PAD als, and the posterior tibial pulse is absent >1.30* Poorly compressible in Diabetes in 2.0%. Nevertheless, the absence of both *Suggests poorly compressible arteries The initial assessment of PAD in pedal pulses, when assessed by a person at the ankle level due to medial arte- patients with diabetes should begin with a experienced in this technique, strongly rial calcification and renders the medical history and physical examination suggests the presence of vascular disease. diagnosis of PAD by ABI alone less to help identify those patients with PAD reliable. risk factors, symptoms of claudication, rest Noninvasive evaluation for PAD: ABI. pain, and/or functional impairment. There As stated earlier, the ABI is a reproducible
  3. 3. Issue 6 Diabetes & Cardiovascular Disease Review 3 and reasonably accurate, noninvasive tion of PAD. In patients with PAD, tobacco lar endpoints when compared with indi- measurement for the detection of PAD and use is associated with increased progres- viduals without PAD, thus demonstrating the determination of disease severity. sion of atherosclerosis as well as increased that ramipril was effective in lowering the ABI is measured by placing the patient risk of amputation.11 Smoking cessation risk of fatal and nonfatal ischemic events in a supine position for 5 minutes. Systolic intervention, including medications if among all patients. Nonetheless, the blood pressure is measured in both arms, required, counseling, and avoidance of all potential benefit of ACE inhibitors has not and the higher value is used as the denom- tobacco products, is essential. been studied in prospective, randomized inator of the ABI. Systolic blood pressure is Glycemic control. Hyperglycemia may trials in patients with PAD. Such trials are then measured in the dorsalis pedis and be a cardiovascular risk factor in individu- needed before making definite treatment posterior tibial arteries by placing the cuff als with PAD; however, evidence for the recommendations regarding the use of an just above the ankle. The higher value is benefit of tight glycemic control in amelio- ACE inhibitor as a unique pharmacologi- the numerator of the ABI in each limb. rating PAD is lacking. In the U.K. cal agent in the treatment of PAD. The diagnostic criteria for PAD based on Prospective Diabetes Study (UKPDS), Dyslipidemia. Although treating the ABI are listed in Table 1, and criteria intensive glycemic control reduced dyslipidemia decreases cardiovascular for testing for PAD using the ABI are diabetes-related endpoints and diabetes- morbidity and mortality in general, no included in Table 2. related deaths.12 However, it was not studies have directly studied the treatment associated with a significant reduction in of lipid disorders in patients with PAD. In Additional evaluation. Additional testing the risk of amputation due to PAD. In fact, a meta-analysis of randomized trials in may include the following: the major reduction in adverse endpoints patients with PAD and dyslipidemia Vascular lab evaluation, segmental was due to improved microvascular rather treated by a variety of therapies, Leng et pressures, and pulse volume recordings: than macrovascular endpoints. Although it al.16 reported a nonsignificant reduction in Performed in the patient with diagnosed is likely that many patients with PAD were mortality and no change in nonfatal PAD to assess location and severity. These included in this study, the prevalence of cardiovascular events. However, the sever- tests also should be considered for patients PAD was not defined; therefore, conclu- ity of claudication was reduced by with poorly compressible vessels or sions may not directly relate to patients lipid-lowering treatment. Similarly, in a patients with a normal ABI where there is with diabetes and PAD. Nevertheless, subgroup analysis of the Scandinavian high suspicion of PAD. good glycemic control (A1C <7.0%) Simvastatin Survival Study (4S), the Treadmill functional testing: To help should be a goal of therapy in all patients reduction in cholesterol level by simvas- with diagnosis in patients with atypical with PAD and diabetes to prevent tatin was associated with a 38% reduction symptoms or a normal ABI with typical microvascular complications. in the risk of new or worsening symptoms symptoms of claudication; may also be Hypertension. Hypertension is associ- of intermittent claudication.17,18 In the used as an evaluation of treatment efficacy ated with the development of Heart Protection Study, adults with coro- and as an assessment of physical function. atherosclerosis as well as with a two- to nary disease, other occlusive arterial Other studies: Further studies (e.g., toe threefold increased risk of claudication.13 disease, or diabetes were randomly allo- pressure, transcutaneous partial pressure In the UKPDS, diabetes endpoints and cated to receive simvastatin or placebo.19 of oxygen) may help with clinical deci- risks of strokes were significantly reduced, A significant reduction in coronary death sion-making regarding revascularization. and risk of MI was nonsignificantly rate was observed in people with PAD, but Sonography or magnetic resonance reduced by tight blood pressure control.14 the reduction was no greater than the angiogram may also be valuable for Risk for amputation due to PAD was not effect of the drug on other subgroups. patients in whom revascularization is reduced. In general, the effects of treating Thus, although there are no data showing being considered. hypertension on atherosclerotic disease or direct benefits of treating dyslipidemia in on cardiovascular events have not been individuals with both PAD and diabetes, Medical Treatments directly evaluated in patients with both dyslipidemia in diabetes patients should PAD and diabetes. Nevertheless, consen- be treated according to published guide- Treatment of systemic atherosclerosis sus strongly supports aggressive blood lines, which recommend a target LDL associated with PAD. Although there is pressure control (<130/80 mmHg) in cholesterol level <100 mg/dl. Following little prospective data showing that treat- patients with PAD and diabetes to reduce this guideline, it is our belief that lipid- ing cardiovascular risk factors will cardiovascular risk. lowering treatment may not only decrease improve cardiovascular outcomes in Results of the Heart Outcomes cardiovascular deaths, but may also slow people with both PAD and diabetes specif- Prevention Evaluation (HOPE) study the progression of PAD in diabetes. ically, consensus strongly supports such showed that ramipril, an ACE inhibitor, Antiplatelet therapy. The Antiplatelet interventions, given that both PAD and significantly reduced the rate of cardiovas- Trialists’ Collaboration reviewed 145 diabetes are associated with significantly cular death, MI, and stroke in a broad randomized studies in an effort to evaluate increased risks of cardiovascular events. range of high-risk patients without hyper- the efficacy of prolonged treatment with Cigarette smoking. Cigarette smoking is tension.15 Of the 9,297 patients in this antiplatelet agents (in most cases, the single most important modifiable risk study, 4,051 had PAD. Patients with PAD aspirin).20 This meta-analysis combined factor for the development and exacerba- had a similar reduction in the cardiovascu- data from >100,000 patients, including
  4. 4. 4 Diabetes & Cardiovascular Disease Review Issue 6 70,000 high-risk patients with evidence of Exercise therapy has minimal associated ischemic ulcers are commonly seen cardiovascular disease. A 27% reduction morbidity and is likely to improve the around the edges of the foot, including the in odds ratio in the composite primary cardiovascular risk factor profile. In nearly apices of the toes and the back of the heel. endpoint (MI, stroke, and vascular death) all studies, unsupervised exercise regimens They are generally associated with a was found for high-risk patients compared have shown lack of efficacy in improving pivotal event: trauma or wearing unsuit- with control subjects. However, when a functional capacity. able shoes. Important aspects of subset of >3,000 patients with claudica- Pharmacological therapies. Two agents conservative management include tion was analyzed, effects of antiplatelet have been approved by the FDA for treat- debridement, offloading the ulcer, appro- therapy were not significant. Thus, the use ing claudication: priate dressings, and adjunctive wound of aspirin to prevent cardiovascular events ■ Pentoxifylline: Results of postapproval healing techniques.27 Prompt and timely and death in patients with PAD is trials suggest that it does not increase referral of the patient to appropriate foot considered equivocal; however, aspirin walking distance to a clinically mean- care and vascular specialists is critical. therapy for people with diabetes is ingful extent. Debridement. Debridement should recommended.21 ■ Cilostazol: Significant benefit has been remove all debris and necrotic material to The Clopidogrel versus Aspirin in demonstrated in increasing maximal render infection less likely. The preferred Patients at Risk of Ischemic Events walking time in addition to improving method is frequent sharp debridement (CAPRIE) study evaluated aspirin versus functional status and health-related with a scalpel, normally undertaken at the clopidogrel in >19,000 patients with quality of life.25 This drug is contraindi- hospital bedside or in the outpatient recent stroke, MI, or stable PAD.22 The cated if heart failure is present because setting. Indications for surgical debride- study results showed that 75 mg clopido- of concerns about arrhythmias. In one ment include the presence of necrotic grel per day was associated with a relative trial, pentoxifylline was inferior when tissue, localized fluctuance, and drainage risk reduction of 8.7% compared with the compared with treatment with cilosta- of pus or crepitus with gas in the soft benefits of 325 mg aspirin per day for a zol.26 Cilostazol is the drug of choice if tissues on X-ray. composite endpoint (MI, ischemic stroke, pharmacological therapy is necessary Footwear. With the neuroischemic foot, and vascular death). More striking, in a for the management of PAD in patients the chief aim is to protect the foot from subgroup analysis of >6,000 patients with with diabetes. pressure and shear. Ulcers may be PAD, clopidogrel was associated with a Preventative foot care. All patients with prevented from healing if the patient risk reduction of 24% compared with diabetes and PAD should receive preventa- wears snug shoes or slip-on styles. It is aspirin. Clopidogrel was shown to be as tive foot care with regular supervision to most important that the shoe does no well tolerated as aspirin. Based on these minimize the risks of developing foot harm. A shoe that is sufficiently long, results, clopidogrel was approved by the complications and limb loss.10 broad, and deep and fastens with a lace or U.S. Food and Drug Administration strap high on the foot may be all that is (FDA) for the reduction of ischemic events Treatment of the ischemic foot. CLI needed to protect the margins of the foot in all patients with PAD. In the CAPRIE portends limb loss and requires urgent and allow healing of the ulcers. Special study, about one-third of the patients in treatment. The frequent presence of footwear, such as sandals or braces, may the PAD group had diabetes. In those neuropathy strongly influences the clinical be necessary. patients, clopidogrel was also superior to presentation. The presence of neuropathy Dressings. Nonadherent dressings aspirin therapy. blunts pain perception, allowing a later should cover diabetic foot ulcers at all In summary, patients with diabetes presentation with more severe lesions than times. No single ideal dressing exists, and should be on an antiplatelet agent (e.g., in the nondiabetic patient. In a vicious there is no evidence that any one dressing aspirin or clopidogrel) according to cycle, the presence of PAD increases nerve is better for the diabetic foot than any current guidelines.21 Individuals with ischemia, resulting in worsened neuropa- other. However, the following properties diabetes and PAD may benefit more by thy. In addition, such arterial lesions may are desirable: ease of removal from the taking clopidogrel. progress undetected for long intervals foot and ability to accommodate pressures because of the distal distribution, making of walking without disintegrating. Treatment of symptomatic PAD. the severity of the underlying PAD often Occlusive dressings may lower the risk of Medical therapy for intermittent claudica- underestimated. Accordingly, diabetes infection. tion currently suggests exercise patients with PAD are more likely to pres- rehabilitation as the cornerstone of ther- ent with advanced disease than Treatment of infection. Although ulcers apy, as well as the potential use of nondiabetic patients. often become infected, the signs and pharmacological agents. The “neuroischemic” foot—with PAD symptoms of foot infection are diminished Exercise rehabilitation. Randomized and neuropathy—is more prone to trau- in patients with diabetes. The early warn- controlled trials have demonstrated the matic ulceration, infection, and gangrene. ing signs of infection may be subtle benefit of supervised exercise training in Each complication requires specific because of an impaired neuroinflamma- individuals with PAD.23,24 These programs management as well as treatment of the tory response. Furthermore, it may be call for at least 3 months of intermittent underlying ischemia. In contrast to the difficult to differentiate between the treadmill walking three times per week. plantar location of neuropathic ulcers, erythema of cellulitis and the rubor of Continued on page 7
  5. 5. Make the Link! Patient Page All About Peripheral Arterial Disease What is peripheral arterial disease? How do I know whether I’m at Peripheral arterial disease, also called PAD, occurs high risk for PAD? when blood vessels in the legs are narrowed or Just having diabetes puts you at risk, but your risk is blocked by fatty deposits. Blood flow to your feet even greater if and legs decreases. If you have PAD, you have an increased risk for heart attack and stroke. One out of ❏ you smoke every three people with diabetes over the age of 50 is ❏ you have high blood pressure estimated to have this condition. However, many ❏ you have abnormal blood cholesterol levels individuals with warning signs do not realize that they have PAD and therefore do not get treatment. ❏ you already have heart disease or have had a heart attack or a stroke What does diabetes have to do ❏ you’re overweight with PAD? ❏ you’re not physically active If you have diabetes, you’re much more likely to have ❏ you’re over age 50 PAD, a heart attack, or a stroke. But you can cut ❏ you have a family history of heart disease, heart your chances of having those problems by taking attacks, or strokes special care of your blood vessels. You can’t change your age or your family history, but taking care of your diabetes and the conditions What are the warning signs of PAD? that come with it can lower your chances of having Many people with diabetes and PAD do not have any PAD. It’s up to you. symptoms. Some people may experience mild leg pain or trouble walking and believe that it’s just a sign of getting older. Others may have the following symptoms: ❏ leg pain, particularly when walking or exercising, which disappears after a few minutes of rest ❏ numbness, tingling, or coldness in the lower legs or feet ❏ sores or infections on your feet or legs that heal slowly
  6. 6. All About Peripheral Arterial Disease Make the Link! Patient Page How is PAD diagnosed? How is PAD treated? The ankle brachial index (ABI) is one test used to People with PAD are at very high risk for heart diagnose PAD. This test compares the blood pressure attacks and stroke; therefore, it is very important that in your ankle to the blood pressure in your arm. If cardiovascular risk factors be managed. Follow these the blood pressure in the lower part of your leg is steps: lower than the pressure in your arm, you may have ❏ Get help to quit smoking. Your health care PAD. An expert panel brought together by the provider can help you. American Diabetes Association recommends that people with diabetes over the age of 50 have an ABI ❏ Aim for an A1C below 7. The A1C test measures to test for PAD. People with diabetes younger than your average blood sugar over the past 2 to 3 50 may benefit from testing if they have other PAD months. risk factors. ❏ Lower blood pressure to less than 130/80. These other tests can also be used to diagnosis PAD: ❏ Get your LDL cholesterol below 100. ❏ Angiogram: A test in which dye is injected into ❏ Talk to your health care provider about taking the blood vessels using a catheter and X-rays are aspirin or other antiplatelet medicines. These taken to show whether arteries are narrowed or medicines have been shown to reduce heart blocked. attacks and stroke in people with PAD. ❏ Ultrasound: A test using sound waves to produce Studies have found that exercise, such as walking, images of the blood vessels on a viewing screen. can be used both to treat PAD and to prevent it. Medications may help relieve symptoms. ❏ MRI (magnetic resonance imaging): A test using In some cases, surgical procedures are used to treat special scanning techniques to detect blockages PAD: within blood vessels. ❏ Angioplasty, also called balloon angioplasty: A procedure in which a small tube with a balloon Real-Life Stories from People with Diabetes attached is inserted and threaded into an artery; Last summer my leg muscles had been hurting, even then the balloon is inflated, opening the narrowed when I walked a short distance. The pain would stop artery. A wire tube, called a stent, may be left in when I rested but then it would come back. At first, I place to help keep the artery open. thought it was just old age. I told my health care team about the pain and also mentioned that there was a ❏ Artery bypass graft: A procedure in which a sore on my foot that wasn’t healing. They did some blood vessel is taken from another part of the tests and said I had PAD. Now the pain is gone — I’m body and is attached to bypass a blocked artery. taking pills for the PAD and I go for a walk almost every day. — Sylvia P age 60 • type 2 diabetes ., American Diabetes Association 1–800–DIABETES (342–2383) www.diabetes.org
  7. 7. Issue 6 Diabetes & Cardiovascular Disease Review 7 Peripheral Arterial Disease Indications for revascularization. The loss, and identify a patient at high risk of Continued from page 4 indications for limb revascularization are MI, stroke, and death. The diagnosis is disabling claudication or CLI (rest pain or made with a determination of the ABI. ischemia. The redness of ischemia, which tissue loss) refractive to conservative ther- Treatment of the patient with diabetes is most marked on dependency, will apy. Disabling claudication is a relative, and PAD should be twofold: 1) primary disappear on elevation of the limb, not absolute, indication and requires and secondary cardiovascular disease risk whereas that of cellulitis will remain irre- significant patient consultation. One must factor modification and 2) treatment of spective of foot position. Infections in the weigh existing symptoms against the risk PAD symptoms (claudication and CLI) diabetic foot are often polymicrobial; of the procedure and its expected effect and limiting progression of disease. ■ broad spectrum antibiotics are initially and durability. Although most ischemic References indicated. Severe infections require intra- limbs can be revascularized, some cannot. venous antibiotic therapy and urgent Lack of a target vessel, unavailability of the 1 Murabito JM, D’Agostino RB, Silbershatz H, Wilson WF: Intermittent claudication: a risk assessment of the need for surgical autogenous vein, or irreversible gangrene profile from the Framingham Heart Study. drainage and debridement. beyond the mid-foot may preclude revas- Circulation 96:44–49, 1997 Both wet and dry gangrene can occur cularization. In such patients, a choice 2 Hiatt WR: Medical treatment of peripheral in the neuroischemic foot. Wet gangrene is must be made between prolonged medical arterial disease and claudication. N Engl J Med caused by a septic arteritis, secondary to therapy and primary amputation. 344:1608–1621, 2001 soft tissue infection or ulceration. Gas in Major amputation in the neurois- 3 Criqui MH: Peripheral arterial disease: the soft tissues is a serious finding that chemic foot is necessary and indicated epidemiological aspects. Vascular Medicine 6 requires an immediate trip to the operat- only when there is overwhelming infec- (Suppl. 1):3–7, 2001 ing room for open drainage of all infected tion that threatens the patient’s life, when 4 Bernstein EF Fronek A: Current status of non- , spaces and intravenous broad-spectrum rest pain cannot be controlled, or when invasive tests in the diagnosis of peripheral antibiotics. It is important to emphasize extensive necrosis secondary to a major arterial disease. Surg Clin North Am 62:473–487, 1982 that medical treatment of infection with arterial occlusion has destroyed the foot. antibiotics alone is insufficient to resolve Using these criteria, the number of major 5 Elhadd TA, Robb R, Jung RT, Stonebridge PA, Belch JJF: Pilot study of prevalence of asymp- the majority of diabetic foot infections. limb amputations should be limited. tomatic peripheral arterial occlusive disease in Incision and drainage is the basic tenet Most amputations can be prevented patients with diabetes attending a hospital of treatment for nearly all infections of the and limbs salvaged through a multi-armed clinic. Practical Diabetes Int 16:163–166, 1999 diabetic foot. Sometimes amputation of a treatment of antibiotics, debridement, 6 Hirsch AT, Criqui MH, Treat-Jacobson D, toe, toes, or ray(s) may be necessary to revascularization, and staged wound Regensteiner JG, Creager MA, Olin JW Krook , establish drainage. Salvage of the diabetic closure. On the other hand, amputation SH, Hunninghake DB, Comerota AJ, Walsh foot is usually possible but may require may offer an expedient return to a useful ME, McDermott MM, Hiatt WR: Peripheral arterial disease detection, awareness, and aggressive debridement and revasculariza- quality of life, especially if a prolonged treatment in primary care. JAMA tion. Postoperatively, there may be course of treatment is anticipated with 286:1317–1324, 2001 considerable tissue deficit or exposure of little likelihood of healing. Diabetes 7 Weitz JI, Byrne J, Clagett GP Farkouh ME, , bone or tendon. In such circumstances, patients should have full and active reha- Porter JM, Sackett DL, Strandness DE Jr, the foot should be revascularized as indi- bilitation after amputation. Decisions Taylor LM: Diagnosis and treatment of cated and soft tissue deficits may be should be made on an individual basis chronic arterial insufficiency of the lower repaired by reconstructive surgery at a with rehabilitative and quality-of-life issues extremities: a critical review. Circulation 94:3026–3049, 1996 latter stage. A vacuum-assisted wound considered highly. closure device provides topical subatmos- 8 Dormandy JA, Rutherford RB: Management of peripheral arterial disease (PAD): TASC pheric pressure that is most helpful in Conclusions Working Group: TransAtlantic Inter-Society staged procedures. PAD is a common complication in Concensus (TASC). J Vasc Surg 31:S1–S296, Dry gangrene is secondary to a severe patients with diabetes. In contrast to PAD 2000 reduction in arterial perfusion and occurs in nondiabetic individuals, PAD in 9 Dolan NC, Liu K, Criqui MH, Greenland P , in chronic critical ischemia. Revascular- diabetic patients is more prevalent and, Guralnik JM, Chan C, Schneider JR, ization should be initially carried out, because of the distal territory of vessel Mandapat AL, Martin G, McDermott MM: followed by surgical debridement. If revas- involvement and its association with Peripheral artery disease, diabetes, and reduced lower extremity functioning. Diabetes cularization is not possible, surgical peripheral neuropathy, it is more Care 25:113–120, 2002 debridement or amputation should be commonly asymptomatic. Patients with 10 American Diabetes Association: Preventive considered if the necrotic toe or any other PAD and diabetes thus may present later foot care in people with diabetes (Position area of necrosis is painful or if the circula- with more severe disease and have a Statement). Diabetes Care 27 (Suppl. 1):63– tion is not severely impaired. Otherwise, greater risk of amputation. Moreover, the S64, 2004 the necrosis should be allowed to autoam- presence of PAD is a marker of excess 11 Lassila R, Lepantalo M: Cigarette smoking and putate, because a surgical procedure may cardiovascular risk. It is important to diag- the outcome after lower limb arterial surgery. result in further necrosis and a higher level nose PAD in patients with diabetes to elicit Acta Chir Scand 154:635–640, 1988 of amputation. symptoms, prevent disability and limb 12 UK Prospective Diabetes Study (UKPDS)
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